Catalytic converter



Nov. 23, 1943. REEVES 2,335,026

CATALYTIC CONVERTER Filed Nov. 9, 1940 2 SheetsSheet l Nov. 23, 1943. E. D. REEVES 2,335,026

CA'IALY'. I I C CONVERTER Filed Nov. 9, 1940 2 Sheets-Sheet 2 $754M mar 1 More: 007157 Patented Nov. 23, 1943 CATALYTIC CONVERTER Edward I). Reeves, Cranford, N. J., assignor' to Standard Oil Development Company, a-corporation of Delaware Application November 9, 1940, Serial No. 364,951

2 Claims.

The present invention relates to improvements in catalytic apparatus, and the said invention is fully described in the following specification and claims.

My invention relates to a chemical plant adapted to provide means for continuously carrying out chemical reactions such as the cracking of gas oil vapors in the presence of a solid catalyst material. As is generally known, when hydrocarbon oils such as gas oil are cracked in the presence of a solid catalyst, such as an acid treated clay contained in a reactor or converter in the form of one or more beds or layers, the process results in the deposition of coke upon the catalyst with the result that the cracking operation must be periodically discontinued in order to regenerate the catalyst and remove the contaminating coke. Where the process is carried out in a reactor containing one or more stationary beds of catalyst, the shut-downs necessary to regenerate the catalyst are troublesome and, of course, result in the diminution-of the time when the operation is in the productive phase.

My present invention relates to a means adapted to cause motionof catalyst continuously through the cracking zone, the catalyst being residient in the zone for a period when it is-active and thereafter being removed and caused to move through a purging zone, a regeneration zone, a second purging zone, and thereaftenhaving been regenerated and purged, moved back into the crackingzone. The meanswhich I provide to carry out these operations continuously consist essentially of a tunnel-like structure disposed in the form of a rectangle and Within the rectangular tunnel there are disposed a plurality of catalyst receptacles or canisters adapted to contain catalyst and having two oppositely disposed perforated side or vertical Walls. The canisters are of such dimensions as to nearly completely correspond to the internal dimensions of the tunnel, just suflicient clearance being allowed to permit movement of the canisters through the tunnel.

In the accompanying drawings, Fig I is a perspective view of my chemical plant; Fig. II is a cross-section of the plant; Fig. III shows an end view of one of the canisters; and Fig. IV shows a side view of the canister Referring in detail to Figs. I to III, I represents an endless closed tunnel disposed in four sections in the form of a rectangle. The section represented by C is the cracking section, the section represented by P is the purging section, the section represented by R is the regeneration section, and the section represented by Q is a second purging section. Also disposed within the tunnel are the canisters Ill which have oppositely disposed perforated side walls I I. The canisters are of suflicient-size to occupy substantially the entire space between side walls l5 and I6 of the tunnel. Furthermore, the canisters are supported on a plurality of rollers 20 providing means, together with some driving means (not shown) for causing the movement of the canisters'through the tunnel. The rollers 20 rest on the base portion 25 of the tunnel, and the canisters supported on the rollers extend upwardly a sufiicient distance to nearly fill the space be-- tween the rollers and the roof 30 of the tunnel. The walls 8 and 9 of canisters Ill are imperiorate.

In operation the preheated hydrocarbon oil, such as gas oil heated to a temperature of 850 is discharged into the tunnelthrough inlet 35, and the vapors pass through the series of canisters containing catalyst by entering through the perforated wall H and'discharging through the oppositely disposed perforated wall. This fiow continues through the canisters in the cracking section C, the vapors finally being withdrawn through outlet 48. As the vapors are forced through the catalyst contained in the canisters,

r the said canisters move continuously toward purging section P. When a canister has reached the purging section P, it is then caused to move in a direction which is at right angles to that in the cracking section C, but without turning the canister, as indicated in Fig. I. In purging section P, steam or some other inert gas at a temperature of 850 F. is introduced through line Al, and the purging gas is discharged into the canisters through the perforated wall H and is removed. through the opposite perforated wall. The pressure of the steam in purging section P is in excess or" that prevailing in cracking section C, thuspreventin'g the now of hydrocarbon vapors into the purging section P, and greater than in regeneration section R hereinafter described. The result of the purging operation is to remove volatile hydrocarbons from the spent catalyst and these, together with the purging gas, are withdrawn through discharge line 45. As in the case of the canisters in cracking section C, canisters in purging section P move forwardly toward regeneration section R. When a canister has reached regeneration section B, it is caused to move in a direction which is at right'angles to its movement in purging section P. A regeneration gas, such as air, air diluted with'nitrogen, fiue'gas, steam or the like'to the ex'tent'th'a't'it contains from 2% to 20% free oxygen is discharged into regeneration section R a'nd'is' thereafter forced through the series or line 'o'fcanisters disposed in saidse'ction. The regeneration gas issufi'iciently heated to cause combustionof the catalyst contaminants? The regeneration gasi's discharged from the regeneration section C through conduit 5 I. After a canister has reached treated in purging section P, steam entering through inlet 55 and being withdrawn through" discharge conduit 56. The pressure maintained in the purging gas in purging section Q is greater than that in regeneration section B, thus preventing the flow of either hydrocarbon vapors or regeneration gas into said section. As previously indicated, the pressure in purging section;

P is greater than the gas pressure in cracking section C and is also greater than the gas pressure in regeneration section R. a

Any suitable means may be provided for causing the motion of the canisters through the sev-- eral sections of the tunnel. For instance, the several canisters in any section may be connected together by a proper linkage or coupling means, and the entire line may be pulled through the section by means of a chain or cable, or the can-' isters may be urged or pushed forwardly by a hydraulic ram or the like. In order to permit the ingress or exit of canisters'into the tunnel from the outside, the wall l5 may be constructed of a plurality of removable plates in the region of W, the number and size of the plates being suflicient to permita canister to be removed at this point by removal of the plates. The power necessary to cause the movement of the canisters is preferably from a source outside the tunnel, and the transmission means projecting into the tunnel are sealed against the escape of vapors at the point where the cable or ram projects into the tunnel by means'known in the cracking art.

My invention is not limited to the precise details hereinbefore set forth and numerous modifications of the invention will be readily apparent to those skilled in the art; For instance, it is within the scope of my invention to provide a closed tunnel in the form of a ring which is sub divided into a cracking section, regeneration section and two purging sections.

To recapitulate, my apparatus as hereinbefore described provides means in which catalytic operations may be carried out without interrruption, and the means consist essentially of a closed endless tunnel inwhich are disposed a plurality of canisters having two oppositely disposed perforated vertical walls, theother two vertical walls being imperforated. By the form and arrangement described, it is unnecessary to connect the gas conduit means directly to' the canisters, the oil vapors, steam and purging gas being discharged in their proper section. It will be noted that the hydrocarbon vapors in the cracking section are confronted with imperforated walls 9 of the canisters against flow into the purging sections P and Q, and the only vapors which could penetrate into the purging sections are those which might leak around the sides or over the top and beneath the bottom of the canisters. This tendency of seepage of hydrocarbon vapors into the purging sections is further counteracted by maintaining a greater gas pressure in the purging sections. There will be a small amount of regeneration gas and hydrocarbon vapors present in the purging sections, but these amounts will be negligible,

It is also within the scope of my invention to pass either cracking or regeneration gases concurrent or countercurrent to the direction in which the canisters are moving.

'What I claim is:

1. In combination with a closed endless tunnel formed of straight sections meeting at right "angles and providing a cracking section, a regeneration section and two purging sections be- [tween said cracking and regeneration sections,

means for introducing gases into the cracking and regeneration sections, a plurality of canisters adapted to contain a solid catalyst material, said canisters having two oppositely disposed perforate vertical walls and two oppositely disposed vertical imperforate Walls, the I said canisters being of such dimensions as to correspond closely with the internal dimensions of said tunnel, the said canisters being adapted to be moved around through said tunnel forwardly and'backwardly respectively throughv said cracking and regeneration sections and without turning laterally through said purging sections and being disposed in the said cracking and regeneration sections in such a manner as to present the perforate walls to the flow of gases in said sections whereby the said gases pass through the canisters in contact with'the catalyst i'n'the cracking and regeneration. sections and to present imperforate walls to the flow of said cracking and regeneration gases in the said purging sections and means for withdrawing gases from the cracking and regeneration sections respectively. 2. In combination with a closed. endless tunnel formed of straight sections meeting at right angles and providing a cracking section, a regeneration section and two purging sections between said cracking and regeneration sections, means for introducing hydrocarbons into one end of said straight section forming the cracking section, means for withdrawing cracked products from the other end of said crackingsection, means for introducing gas into one end of said regeneration section, means for withdrawing regeneration gases fromtheother end of said're generation section, a plurality of movable individual canisters in each of said sections and adapted to contain solid catalyst andbeing of such dimensions to correspond closely with the internal dimensions of said tunnel, each of said canistershaving end perforate Walls and'imper forate remaining wallswhereby the hydrocarbons pass in series flow through said' perforate walls of a series of said canisters in said cracking section and gases pass in series flow through said perforate walls of a series of said canisters in said regeneration section in substantially 'straightpaths, means for moving said canisters forwardly through said cracking section and -in an opposite direction in said regeneration'section and without turning said canisters moving them laterally through'said purgingfsections, said imperforate walls preventing substantiakfiow of vapors and gases fromsaid-cra'cking androgen eration sections to" said purging sections and means for introducing purging gas into said purging sections whereby the'purging gas flows through said perforate ends of said laterally moving canisters; EDWARD D. REEVES;- 

